Q1 of 84 Page 5

Evaluate each of the following using identities:

(i)


(ii) (2x+y) (2x-y)


(iii)


(iv) (a – 0.1) (a +0.1)


(v)

(i) We know, (a-b)2 = a2 + b2 -2ab


(ii) We know, (a-b)2 = (a+b) (a-b)


(2x+y) (2x-y) = (2x)2– y2 = 4x2 – y2


(iii) We know, (a-b)2 = a2 + b2 -2ab



(iv) We know, (a-b)2 = (a+b) (a-b)


(a – 0.1) (a +0.1) = (a)2– (0.1)2


= a2 – 0.01


(v) We know, (a-b)2 = a2 - b2



More from this chapter

All 84 →
2

Evaluate each of the following using identities:

(i) (399)2


(ii) (0.98)2


(iii) 991×1009


(iv) 117×83

 3

Simplify each of the following:

(i) 175 × 175 + 2 × 175 × 25 + 25 ×25


(ii) 322 × 322 – 2 × 322 × 22 + 22 × 22


(iii) 0.76 ×0.76+2×0.76×0.24+0.24×0.24


(iv)

4

If x + = 11, find the value of x2 +

 5

If x - = -1, find the value of x2 +